/*
 * Copyright (c) 2018-2020 "Graph Foundation,"
 * Graph Foundation, Inc. [https://graphfoundation.org]
 *
 * This file is part of ONgDB Enterprise Edition. The included source
 * code can be redistributed and/or modified under the terms of the
 * GNU AFFERO GENERAL PUBLIC LICENSE Version 3
 * (http://www.fsf.org/licensing/licenses/agpl-3.0.html) as found
 * in the associated LICENSE.txt file.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 */
/*
 * Copyright (c) 2002-2018 "Neo Technology,"
 * Network Engine for Objects in Lund AB [http://neotechnology.com]
 *
 * This file is part of Neo4j.
 *
 * Neo4j is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 */
package org.neo4j.cypher.internal.runtime.slotted.expressions

import org.neo4j.cypher.internal.runtime.interpreted.ExecutionContext
import org.neo4j.cypher.internal.runtime.interpreted.commands.expressions.{Expression, PathValueBuilder}
import org.neo4j.cypher.internal.runtime.interpreted.pipes.QueryState

object SlottedProjectedPath {

  type Projector = (ExecutionContext, QueryState, PathValueBuilder) => PathValueBuilder

  object nilProjector extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = builder
  }

  case class singleNodeProjector(node: Expression, tailProjector: Projector) extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = {
      val nodeValue = node.apply(ctx, state)
      tailProjector(ctx, state, builder.addNode(nodeValue))
    }
  }

  case class singleIncomingRelationshipProjector(rel: Expression, tailProjector: Projector) extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = {
      val relValue = rel.apply(ctx, state)
      tailProjector(ctx, state, builder.addIncomingRelationship(relValue))
    }
  }

  case class singleOutgoingRelationshipProjector(rel: Expression, tailProjector: Projector) extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = {
      val relValue = rel.apply(ctx, state)
      tailProjector(ctx, state, builder.addOutgoingRelationship(relValue))
    }
  }

  case class singleUndirectedRelationshipProjector(rel: Expression, tailProjector: Projector) extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = {
      val relValue = rel.apply(ctx, state)
      tailProjector(ctx, state, builder.addUndirectedRelationship(relValue))
    }
  }

  case class multiIncomingRelationshipProjector(rel: Expression, tailProjector: Projector) extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = {
      val relListValue = rel.apply(ctx, state)
      tailProjector(ctx, state, builder.addIncomingRelationships(relListValue))
    }
  }

  case class multiOutgoingRelationshipProjector(rel: Expression, tailProjector: Projector) extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = {
      val relListValue = rel.apply(ctx, state)
      tailProjector(ctx, state, builder.addOutgoingRelationships(relListValue))
    }
  }

  case class multiUndirectedRelationshipProjector(rel: Expression, tailProjector: Projector) extends Projector {
    def apply(ctx: ExecutionContext, state: QueryState, builder: PathValueBuilder) = {
      val relListValue = rel.apply(ctx, state)
      tailProjector(ctx, state, builder.addUndirectedRelationships(relListValue))
    }
  }
}

/*
 Expressions for materializing new paths (used by ronja)

 These expressions cannot be generated by the user directly
 */
case class SlottedProjectedPath(symbolTableDependencies: Set[String], projector: SlottedProjectedPath.Projector) extends Expression {
  def apply(ctx: ExecutionContext, state: QueryState) = projector(ctx, state, state.clearPathValueBuilder).result()

  def arguments = Seq.empty

  def rewrite(f: (Expression) => Expression): Expression = f(this)
}

